A hearing device may amplify an external sound and deliver the amplified external sound to a user. The user may better recognize a sound through the hearing device. However, the user may be exposed to various noise environments in everyday lives. Therefore, if the hearing device outputs an audio signal without appropriately removing noise included in the audio signal, the user may feel inconvenient.
Therefore, there is a need for a method of processing an audio signal to reduce a sound quality distortion and remove noise.